Can ford only know if your coils are going bad?

[shstony831]

so here is the problem.
I have an 04 lincoln ls V6
The car has been jerking at times going from 2000rpm to 3000 or 4000 rpm all of a sudden then back down while accelerating. I took the car to where I bought it from since I also had an oil leak in my engine and the warranty company said I had to take it there. They replaced the oil pan gasket and then they also "checked" the coils and said they were fine. They said that there was no history of misfire codes or anything. I had told them before that the CEL had never turned on.
Could the jerking be coils or can it be attributed to something else? Is it more likely that ford will be able to know for sure what the problem is? I have heard of a stress test but don't know much about it.

I originally bought the car from a mazda dealer as a used car and took it back there to have them check for problems. The PCV valve was also replaced in October due to ford having a recall on them apparently.

I searched about the stress test but can't seem to find some good information about it.

 

[joegr]

No, other than Ford can know.

Here's the simple test:

Step 1, identify the vehicle. Is it a Lincoln LS or recent Ford Thunderbird?
Step 2, if the the answer to step 1 was yes, then assume that at least some of the COPs are failing.

Here's the complicated test:

http://www.stangnet.com/images/stories/docs/sn95_TSBs/05-22-08.pdf

 

[myfirstlincoln]

bump

I am having the exact same problem and am hesitant to take my car in simply for them to say, "well the cel isn't on so we don't know what's wrong with it - wait until the cel comes on." Obviously that's a waste of my time and theirs. The question is whether or not a Ford dealer can/will be able to tell which coil is missfiring without a cel.

Btw, I have an 03 LS w/ 80,000 so my coils will be covered under warranty which makes me thing that the stealership won't even bother looking at it until it "breaks" and the cel comes on.

 

[joegr]

...The question is whether or not a Ford dealer can/will be able to tell which coil is missfiring without a cel.

Btw, I have an 03 LS w/ 80,000 so my coils will be covered under warranty which makes me thing that the stealership won't even bother looking at it until it "breaks" and the cel comes on.

Yes, they can tell without any cel (see PDF linked above).
Yes, they will look at it. Ford will pay them if any coils are bad. You will pay them if none of the coils are bad. ($90 diagnostic fee)

 

[XLRVIII]

bump

I am having the exact same problem and am hesitant to take my car in simply for them to say, "well the cel isn't on so we don't know what's wrong with it -

I hate how they do that..

IF a CEL is on, warranty work is authorized..no charge to the customer
IF there is NO CEL then the customer pays for them to diagnose the issue..and then charge the customer to tell him they "they cant reproduce the problem".

SOoooo.
Go out there and unplug two coils, one on each side of the motor
then start the car... wait til the CEL sets, then drive it to the dealership..after reconnecting the coils that you disabled

Usually I wouldn't suggest this, but since the dealerships are screwing folks by waiting til their warranty runs out.. or outright declining to fix COMMON issues.
SCREW EM BACK!

 

[Lincoln Jealous]

those are the most common symptoms for a bad coil(s)

youll see the rpm's jump mostly near 40mph, when the car changes shifts



fix the bad vcg leak or youll be replacing coils like crazy

 

[joegr]

I hate how they do that..

IF a CEL is on, warranty work is authorized..no charge to the customer
IF there is NO CEL then the customer pays for them to diagnose the issue..and then charge the customer to tell him they "they cant reproduce the problem".

SOoooo.
Go out there and unplug two coils, one on each side of the motor
then start the car... wait til the CEL sets, then drive it to the dealership..after reconnecting the coils that you disabled

Usually I wouldn't suggest this, but since the dealerships are screwing folks by waiting til their warranty runs out.. or outright declining to fix COMMON issues.
SCREW EM BACK!

No, that's not how it works with the extended coil warranty.

If one of more coils test as bad using the stress test, then the factory pays.

If none are bad, then you pay the diagnostic fee + any work you allow them to do.

It does not matter if the CEL is on or off, or what if any codes are stored. Even if misfire codes are stored, you will still pay if the coil does not test as bad. If no codes are stored, but a coil fails the stress test, Ford will pay.
It's as simple as that.

The CEL on rule of thumb only applies to the normal warranty (and then only loosely).

 

[shstony831]

hmm i might take it to ford then to see if it's the coils but I don't feel like paying the 90 dollars to just find out lol but might be worth it
when i took the car to the mazda dealership last week, they said it checked out fine in terms of misfiring but all they ran was diagnostics as far as I know. I don't believe they ran a stress test or anything.